Ultraviolet Radiation in the Arctic

In 1987, responding to serious ozone depletion reported in Antarctica, the National Science Foundation established a network of instruments to observe solar ultraviolet (UV) radiation at high latitudes. The network eventually grew to seven sites including two Arctic locations at Barrow, Alaska (71° 19’ N), and Summit, Greenland (72° 34’ N). Data available through ACADIS include measurements of UV radiation and related data products from Barrow starting in 1991 and from Summit starting in 2004. Effective 1-August 2009, the two sites were integrated into NSF’s Arctic Observing Network as part of the NSF AON projects “Ultraviolet Radiation in the Arctic” and, since 2012, “Ultraviolet Radiation in the Arctic: 2012-2015.” Data include spectra of solar spectral irradiance between 280 and 600 nm, biologically effective dose-rates, total ozone, surface albedo, and cloud optical depth. The long time-series provides a unique opportunity to study the effect of a changing environment on UV radiation. Measurements at Summit are ideally suited to probe the free troposphere and study the effects of long-range transport of pollutants and aerosols on UV radiation. Data can also be used for validation of satellite observations, verification of models describing the transfer of radiation through the atmosphere, advancement of climate models, and addressing the SEARCH question whether the Arctic is moving to a new state.

1987年，针对南极洲报告的严重臭氧耗竭问题，美国国家科学基金会（National Science Foundation, NSF）搭建了一套用于高纬度地区太阳紫外线（UV）辐射观测的仪器网络。该观测网络最终扩充至7个站点，其中包括位于阿拉斯加州巴罗（71°19′N）与格陵兰岛萨米特（72°34′N）的两个北极站点。ACADIS可获取的数据包含1991年起来自巴罗、2004年起来自萨米特的紫外线辐射实测数据及相关衍生数据产品。自2009年8月1日起，这两个站点被整合进NSF的北极观测网络（Arctic Observing Network, AON），作为NSF AON项目“北极地区紫外线辐射”的组成部分；自2012年起，该项目更新为“北极地区紫外线辐射：2012-2015”。该数据集涵盖280至600纳米波段的太阳光谱辐照度谱、生物有效剂量率、总臭氧量、地表反照率以及云光学厚度等数据。这套长时序观测序列为研究环境变化对紫外线辐射的影响提供了独特的机遇。其中，萨米特站点的观测数据极为适用于探究自由对流层状况，以及研究污染物与气溶胶的长距离传输对紫外线辐射的影响。此外，这些数据还可用于卫星观测的验证、大气辐射传输模型的校验、气候模型的优化，以及解答SEARCH提出的“北极是否正迈向新的气候状态”这一科学问题。